Hypertension in diabetic nephropathy: prevention and treatment

Hypertension is the major determinant of morbidity and mortality in diabetic patients. In type I diabetes hypertension develops in parallel with the evolution of nephropathy, whereas in type II diabetes hypertension precedes the onset of manifest diabetes mellitus by years or decades. Nephropathy is equally common in types I and II diabetes. Strong genetic determinants for nephropathy have been recognized, but it is unclear whether a genetic predisposition to hypertension and elevated sodium-lithium countertransport are involved. In epidemiologic studies hypertension is related to the risk and rate of evolution of diabetic nephropathy, retinopathy, and cardiovascular complications. The relationship appears to be causal, because antihypertensive treatment attenuates the rate of loss of glomerular filtration. In this respect angiotensin-converting enzyme inhibitors appear to be superior (renal protective action). Calcium channel blockers have been promising in experimental studies, but clinical information is currently incomplete.